[Role of spleen macrophage activation in inhibiting the metastasis of transplantable tumors]

Abstract

The role of macrophages in the development of the inhibitory effect of subcutaneously transplanted tumor on the formation of experimental metastases in the lung was studied. Four murine lines of tumor were investigated in a syngeneic system. The treatment of tumor-bearing mice with antimacrophage agents (carrageenan or silica) proved to stimulate experimental metastasis formation which correlated with the absence of antitumor activity of splenocytes tested in a transfer system (by counting lung metastases). Antitumor activity of the following types of splenocytes of tumor bearers was studied in this system: intact, those treated in vitro with different doses of carrageenan, separated from macrophages by carbon iron and, vice versa, enriched with macrophages. It was shown that (I) antitumor activity of tumor-bearers' splenocytes correlates with the ability of relevant tumors to inhibit experimental lung metastasis formation, (2) the key role in this effect is played by activated macrophages of the spleen, and (3) activation of macrophages is not tumor-specific.